When Twitter Inc (NYSE: TWTR) reported better-than-expected fourth-quarter earnings in early February, not only did investors and the Street applaud it by sending its shares higher, but it also silenced critics who were asking for Dick Costolo to be ousted as the CEO of the company.

Twitter co-founder Biz Stone was on CNBC Friday to discuss what makes Dick Costolo such a good fit for the company. Stone also praised Twitter's president of global revenue Adam Bain for being "incredibly good at his job."

Dick Costolo

"I have drinks with Dick a lot; we are neighbors, and we are good friends, and the reason why Evan [Williams] and I hired Dick in the first place is because we admire his leadership skills," Stone said.

"We have known him from at least 15 years, and we have known him to be a great leader, a really funny guy and that was always a key hiring personality [at] Twitter was, ‘Are they funny?’

"And Dick is a hilarious guy, which is important because humor is kind of a secret delivery mechanism of truth. I think Dick is an extremely good leader."

Adam Bain

He continued, "And I think the executive bench at Twitter is just very deep, very talented. Adam Bain, extremely nice guy, but also incredibly good at his job. Rarely do you have somebody who is so focused and so incredibly good at their Job, but also you'd be happy to stuck in an elevator with them."